Groundswell against concentrated animal feeding operations (CAFOs) is gaining intensity in Iowa with over 100 environmental activist organizations promoting a moratorium on new farms.  At issue is the volume of nitrate entering water resources including rivers that supply municipalities and cities.  Levels of nitrate in drinking water exceed Federal limits in at least eleven water supply systems with over 200 communities faced with undesirable levels of contamination.

Economic pressure and industry consolidation reduced the number of hog farms in Iowa by 80 percent between 1982 and 2007 concurrently with a tenfold increase in hogs housed per farm to 5,000. 

Although Iowa is the leading state for U.S. egg production, hog farms are the major source of animal waste.